Electrical machines which operate in accordance with transverse flux principles consist of an armature winding in the form of a circular coil co-axial with a rotor. The rotor consists of an active rim comprising a multiplicity of magnets and laminated poles, fastened to a rotor disc. The armature winding links the flux generated by the permanent magnets mounted on the rim of the rotor disc by means of a series of stator cores.
The rotor disc may support several rotor rims typically arranged in pairs on opposite sides of the disc. Each rotor rim is circumferential and may consist of a single row of magnets and pole pieces or a double row separated by an insulated spacer.
The retention of magnets in smaller transverse flux motors has been achieved by bonding using an epoxy resin or similar adhesive. Bonding is unsuitable for larger transverse flux motors as larger bending moments need to be taken by the magnets themselves.
The present invention seeks to provide a rotor rim having improved mechanical integrity so that the magnets are retained in the event of failure of the adhesive.